Revert of Remove font cache code

chrome/utility/font_cache_handler_win.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/utility/font_cache_handler_win.h"
+
+#include "base/task_runner_util.h"
+#include "base/threading/thread.h"
+#include "chrome/common/chrome_utility_messages.h"
+#include "content/public/common/dwrite_font_platform_win.h"
+#include "content/public/utility/utility_thread.h"
+
+FontCacheHandler::FontCacheHandler() {
+}
+
+FontCacheHandler::~FontCacheHandler() {
+}
+
+bool FontCacheHandler::OnMessageReceived(const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(FontCacheHandler, message)
+    IPC_MESSAGE_HANDLER(ChromeUtilityHostMsg_BuildDirectWriteFontCache,
+                        OnBuildFontCache)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+void FontCacheHandler::OnBuildFontCache(const base::FilePath& full_path) {
+  DCHECK(!cache_thread_);
+
+  utility_task_runner_ = base::MessageLoop::current()->task_runner();
+
+  // Create worker thread for building font cache.
+  cache_thread_.reset(new base::Thread("font_cache_thread"));
+  if (!cache_thread_->Start()) {
+    NOTREACHED();
+    return;
+  }
+  cache_thread_->message_loop()->PostTask(
+      FROM_HERE, base::Bind(&FontCacheHandler::StartBuildingFontCache,
+                            base::Unretained(this),
+                            full_path));
+}
+
+void FontCacheHandler::StartBuildingFontCache(const base::FilePath& full_path) {
+  content::BuildFontCache(full_path);
+  utility_task_runner_->PostTask(FROM_HERE,
+                                 base::Bind(&FontCacheHandler::Cleanup,
+                                            base::Unretained(this)));
+}
+
+void FontCacheHandler::Cleanup() {
+  cache_thread_.reset();
+  content::UtilityThread::Get()->ReleaseProcessIfNeeded();
+}